The commonly used root-mean-square error for estimation performance evaluation is easily dominated by large error terms. So many new alternative absolute metrics have been provided in X. R. Li's work. However, eac...
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The commonly used root-mean-square error for estimation performance evaluation is easily dominated by large error terms. So many new alternative absolute metrics have been provided in X. R. Li's work. However, each of these metrics only reflects one narrow aspect of estimation performance, respectively. A comprehensive measure, error spectrum, was presented aggregating all these incomprehensive measures. However, when being applied to dynamic systems, this measure will have three dimensions over the total time span, which is not intuitive and difficult to be analysed. To overcome its drawbacks, a new metric, dynamic error spectrum (DES), is proposed in this study to extend the error spectrum measure to dynamic systems. Three forms under different application backgrounds are given, one of which is balanced taking into account both good and bad behaviour of an estimator and so can provide more impartial evaluation results. It can be applied to a variety of dynamic systems directly. Then the challenge in performance evaluation of the interacting multiplemodel (IMM) algorithm is considered, and the IMM algorithm is chosen as the testing case to illustrate the superiority of the DES metric. The simulation results validate its utility and effectiveness.
Multifilter algorithms are usually applied in solving the maneuvering target tracking problem. However, in real, applications, processing time may become impractical. Multiprocessors seem to offer the throughput neede...
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Multifilter algorithms are usually applied in solving the maneuvering target tracking problem. However, in real, applications, processing time may become impractical. Multiprocessors seem to offer the throughput needed for such applications. In this paper, we investigate the performances of Viterbi algorithm and the interacting multiplemodel alogorithm, applied to the tracking problem, when implemented on a general purpose shared-memory and shared-bus MIMD multiprocessor. The computational complexity as well as the speedup and efficiency are examined in detail. It is shown that the computational complexity of the parallel implementation of these algorithms is about the same in both memory space and processing time categories. Efficiency with P processors is about 1 - 1/P for small P and is expected to be relatively high also for large P, especially when many filters and large state and measurement vectors are considered.
For most real-world systems, the exact description of possible faults is unknown, making these faults difficult to detect, and even more difficult to identify. The most promising way is to use multiple hypotheses for ...
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For most real-world systems, the exact description of possible faults is unknown, making these faults difficult to detect, and even more difficult to identify. The most promising way is to use multiple hypotheses for faults to find the best fitting fault model by comparing system measurements with the predictions of the multi-modelalgorithm. However, this may lead to the need for infinite hypotheses. We propose a novel multi-model approach that considers a small number of different models with a known macro-structure and unknown parameters, combining system identification with simultaneous fault diagnosis. The unknown parameters in the models are estimated using a maximum likelihood approach. The fitted models are then used in an interacting multiple model algorithm to determine the most likely model that best describes the system behavior at any moment in time. An overfitting problem emerging from short data sequences is discussed, and two solutions are introduced. First, a regularization term in the probability estimation is suggested to penalize frequent parameter changes that signal possible overfitting. Second, an algorithm with a shifted data set is presented. The effectiveness of the algorithms is demonstrated on a motion tracking problem where the different fault hypotheses represent the macro-behavior of a moving object, and the real system switches between different modes. In a comparison, the proposed algorithms are the only ones that reliably identify the defined faults. They can be easily adapted to other fault diagnosis problems.
Burning Through Point (BTP) state is a very important parameter for sintering process. A lot of researches for the modeling of BTP have been made, but the precise model is not very easy to find, so the prediction base...
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ISBN:
(纸本)9781479937066
Burning Through Point (BTP) state is a very important parameter for sintering process. A lot of researches for the modeling of BTP have been made, but the precise model is not very easy to find, so the prediction based on modeling cannot be carried out effectively. This paper presents fuzzy neural network structure and multiple model algorithms which can process incomplete, ambiguous information and gives an effective model for sintering process. The simulation result is made to show the effectiveness of the proposed algorithm.
A Fault Detection and isolation (FDI) algorithm design is presented using the multiple model algorithm technique for the Bluebird aircraft being developed at the Naval Postgraduate School. The requirement to maintain ...
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A Fault Detection and isolation (FDI) algorithm design is presented using the multiple model algorithm technique for the Bluebird aircraft being developed at the Naval Postgraduate School. The requirement to maintain high performance in the dynamic system of the aircraft necessitates the use of FDI techniques to detect and isolate malfunctions in the sensors and actuators of the aircraft without using hardware redundancy. The solution presented makes use of analytical redundancy in a bank of Kalman filters. Statistical tests using Bayesian theory are applied on the filter's innovations to perform the task of detection and isolation. The algorithm was developed using MATLAB software from The Math Works. Inc. The work presented in this thesis is related only to the task of FDI. The remaining task of the monitoring system, reconfiguration and continued operation by the observed plant after a failure detection, will not be addressed.
A method for unknown input estimation in nonlinear stochastic system is presented. A key problem in bioprocess systems is the absence, in some cases, of reliable on line measurements for real time monitoring applicati...
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A method for unknown input estimation in nonlinear stochastic system is presented. A key problem in bioprocess systems is the absence, in some cases, of reliable on line measurements for real time monitoring applications. In this paper, a software sensor for an anaerobic digester is presented. Unmeasured components of the influent are estimated from available on line measurements. Based on a multiplemodel scheme, a bank of unknown input Kalman filters are discussed to estimate a probabilistic weighting state and unknown input of the process. The performances of the method are tested in simulation using a validated model of an anaerobic fixed bed pilot plant.
Burning Through Point(BTP) state is a very important parameter for sintering process.A lot of researches for the modeling of BTP have been made,but the precise model is not very easy to find,so the prediction based on...
详细信息
ISBN:
(纸本)9781479937097
Burning Through Point(BTP) state is a very important parameter for sintering process.A lot of researches for the modeling of BTP have been made,but the precise model is not very easy to find,so the prediction based on modeling cannot be carried out *** paper presents fuzzy neural network structure and multiple model algorithms which can process incomplete,ambiguous information and gives an effective model for sintering *** simulation result is made to show the effectiveness of the proposed algorithm.
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